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Bosch SR9521X - Starter
Product Overview
The Bosch Starter Motor part number SR9521X is a high-quality replacement part designed for BMW vehicles. Manufactured by Bosch, a trusted name in automotive parts, this starter motor ensures reliable and efficient performance, meeting or exceeding OEM standards. Engineered for various BMW models, it provides a dependable start every time you turn the key. Choose Bosch SR9521X for dependable performance and peace of mind every time you service your vehicle.
Cross Reference Numbers
This Bosch SR9521X is equivalent to or replaces the following part numbers: 12417631558, 12417631559.
Vehicle Compatibility
- BMW M2 3.0L6 (2016–2021)
- BMW M3 3.0L6 (2016–2019)
- BMW M4 3.0L6 (2016–2021)
- BMW 640i 3.0L6 (2014–2019)
- BMW X3 3.0L6 (2011–2016)
- BMW X5 3.0L6 (2014–2018)
- BMW X6 3.0L6 (2014–2018)
- BMW 535i 3.0L6 (2014–2016)
- BMW 740i 3.0L6 (2013–2015)
- BMW ActiveHybrid 3 3.0L6 (2013–2015)
This may also fits other applications. Please use the vehicle selector tool to verify fitment.
Why Shop at eEuroparts.com?
- Proven Expertise: Over 25 years of experience with European vehicles means we know your car inside and out.
- Exclusive Kits That Fitâ„¢ - complete repair solutions with no guesswork
- Fitment Confidence: Our accurate cataloging ensures you get the right part the first time.
- Fast, Reliable Shipping: Orders ship quickly from our U.S.-based warehouses.
- Transparent Pricing: Competitive prices with no hidden fees or surprise charges.
- Established Trust: Serving the European auto community since 2000.
Frequently Asked Questions
What does the Bosch SR9521X Starter do?
The starter motor is a critical component of your vehicle's ignition system. It engages the engine flywheel to start the combustion process, allowing your BMW to start smoothly and efficiently.
How do I know if my Starter needs replacement?
Key symptoms that may indicate a failing starter motor include:
- Engine does not crank or starts intermittently.
- Unusual clicking sounds when turning the ignition key.
- Dashboard lights dimming while trying to start the engine.
Can I install the Bosch SR9521X myself?
Yes, the Bosch SR9521X is designed for easy installation, making it suitable for DIY enthusiasts. However, ensure you follow proper safety precautions and refer to your vehicle's service manual for specific instructions.
What are the symptoms of a faulty Starter?
Common symptoms of a faulty starter motor include difficulty starting the engine, grinding noises, or a complete failure to start. If you experience these issues, it is advisable to check the starter motor for faults.
Why should I choose Bosch for my Starter needs?
Bosch is known for its quality and reliability in the automotive industry. Order Bosch SR9521X today for a factory-correct replacement that restores safety and performance.
Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.
- BrandBosch
- ManufacturerBosch
- MPNSR9521X
- Part TypeStarter
- OE Part Numbers12417631559, 12417631558
- FeaturesMounting Hardware Included : No
Mounting Shims Included : No
New Or Remanufactured : Remanufactured
Nose Cone Material : Aluminum
Nose Cone Type : Closed Nose
Power Rating : 1.5
Prop 65 Warning Label Required? : No
Solenoid Attached : Yes
Starter Finish : Aluminum
Starter Rotation : Clockwise
Voltage : 12
- Fitment
- Fitment TypeVehicle Specific
| Year | Make | Model | Submodel | Notes |
|---|---|---|---|---|
| 2015 | BMW | 435i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2015 | BMW | M235i | Base (3.0 L6 GAS) | |
| 2015 | BMW | X6 | sDrive35i (3.0 L6 GAS) | |
| 2015 | BMW | X6 | xDrive35i (3.0 L6 GAS) | |
| 2015 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2015 | BMW | M4 | Base (3.0 L6 GAS) | |
| 2015 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2015 | BMW | 640i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2015 | BMW | 640i | Base (3.0 L6 GAS) | |
| 2015 | BMW | 640i xDrive | Base (3.0 L6 GAS) | |
| 2015 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2015 | BMW | 435i | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2015 | BMW | 435i xDrive | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2015 | BMW | 435i Gran Coupe | Base (3.0 L6 GAS) | |
| 2015 | BMW | ActiveHybrid 3 | Base (3.0 L6 FHEV) | |
| 2015 | BMW | 740i | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2015 | BMW | 740Li | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2015 | BMW | 740Li xDrive | Base (3.0 L6 GAS) | |
| 2015 | BMW | M235i xDrive | Base (3.0 L6 GAS) | |
| 2015 | BMW | 335i | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2015 | BMW | 335i GT xDrive | Base (3.0 L6 GAS) | Notes: with Start/Stop Feature |
| 2015 | BMW | 335i xDrive | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2015 | BMW | 535i | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2015 | BMW | 535i xDrive | Base (3.0 L6 GAS) | |
| 2015 | BMW | 535i GT | Base (3.0 L6 GAS) | |
| 2015 | BMW | 535i GT xDrive | Base (3.0 L6 GAS) | |
| 2015 | BMW | X4 | xDrive35i (3.0 L6 GAS) | |
| 2015 | BMW | X5 | sDrive35i (3.0 L6 GAS) | |
| 2015 | BMW | X5 | xDrive35d (3.0 L6 DIESEL) | |
| 2015 | BMW | X5 | xDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | 435i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2016 | BMW | X6 | sDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | X6 | xDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | M235i | Base (3.0 L6 GAS) | |
| 2016 | BMW | M235i xDrive | Base (3.0 L6 GAS) | |
| 2016 | BMW | M2 | Base (3.0 L6 GAS) | |
| 2016 | BMW | 640i | Base (3.0 L6 GAS) | |
| 2016 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2016 | BMW | 640i xDrive | Base (3.0 L6 GAS) | |
| 2016 | BMW | 640i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2016 | BMW | 435i | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2016 | BMW | 435i Gran Coupe | Base (3.0 L6 GAS) | |
| 2016 | BMW | 435i xDrive | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2016 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | X4 | M40i (3.0 L6 GAS) | |
| 2016 | BMW | X4 | xDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | X5 | sDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | X5 | xDrive35d (3.0 L6 DIESEL) | |
| 2016 | BMW | X5 | xDrive35i (3.0 L6 GAS) | |
| 2016 | BMW | M4 | Base (3.0 L6 GAS) | |
| 2017 | BMW | X6 | sDrive35i (3.0 L6 GAS) | |
| 2017 | BMW | X6 | xDrive35i (3.0 L6 GAS) | |
| 2017 | BMW | M2 | Base (3.0 L6 GAS) | |
| 2018 | BMW | M3 | Base (3.0 L6 GAS) | |
| 2018 | BMW | M2 | Base (3.0 L6 GAS) | |
| 2018 | BMW | M4 | Base (3.0 L6 GAS) | |
| 2018 | BMW | 640i | Base (3.0 L6 GAS) | |
| 2018 | BMW | 640i xDrive | Base (3.0 L6 GAS) | |
| 2018 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2018 | BMW | 640i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2018 | BMW | X6 | sDrive35i (3.0 L6 GAS) | |
| 2018 | BMW | X6 | xDrive35i (3.0 L6 GAS) | |
| 2019 | BMW | 640i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2019 | BMW | M4 | Base (3.0 L6 GAS) | |
| 2019 | BMW | M4 | CS (3.0 L6 GAS) | |
| 2019 | BMW | X6 | sDrive35i (3.0 L6 GAS) | |
| 2019 | BMW | X6 | xDrive35i (3.0 L6 GAS) | |
| 2019 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2011 | BMW | X3 | xDrive28i (3.0 L6 GAS) | |
| 2011 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2012 | BMW | X3 | xDrive28i (3.0 L6 GAS) | |
| 2012 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2013 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2013 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2013 | BMW | 740Li | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2013 | BMW | 740i | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2013 | BMW | ActiveHybrid 3 | Base (3.0 L6 FHEV) | |
| 2013 | BMW | 740Li xDrive | Base (3.0 L6 GAS) | |
| 2013 | BMW | 640i | Base (3.0 L6 GAS) | |
| 2014 | BMW | X3 | xDrive35i (3.0 L6 GAS) | |
| 2014 | BMW | 640i Gran Coupe | Base (3.0 L6 GAS) | |
| 2014 | BMW | 640i | Base (3.0 L6 GAS) | |
| 2014 | BMW | 640i xDrive | Base (3.0 L6 GAS) | |
| 2014 | BMW | 640i xDrive Gran Coupe | Base (3.0 L6 GAS) | |
| 2014 | BMW | 740i | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2014 | BMW | 740Li | Base (3.0 L6 GAS) | Notes: with 1.5 Kilowatt Starter |
| 2014 | BMW | 740Li xDrive | Base (3.0 L6 GAS) | |
| 2014 | BMW | 435i | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2014 | BMW | 435i xDrive | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2014 | BMW | 335i | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2014 | BMW | 535i GT | Base (3.0 L6 GAS) | |
| 2014 | BMW | 535i GT xDrive | Base (3.0 L6 GAS) | |
| 2014 | BMW | 535i | Base (3.0 L6 GAS) | Transmission Control: Automatic |
| 2014 | BMW | 535i xDrive | Base (3.0 L6 GAS) | |
| 2014 | BMW | ActiveHybrid 3 | Base (3.0 L6 FHEV) | Notes: with Start/Stop Feature |
| 2014 | BMW | 335i xDrive | Base (3.0 L6 GAS) | Transmission Control: Automatic, Notes: with Start/Stop Feature |
| 2014 | BMW | 335i GT xDrive | Base (3.0 L6 GAS) | Notes: with Start/Stop Feature |
| 2014 | BMW | X5 | sDrive35i (3.0 L6 GAS) | |
| 2014 | BMW | X5 | xDrive35d (3.0 L6 DIESEL) | |
| 2014 | BMW | X5 | xDrive35i (3.0 L6 GAS) |
Warranty Overview
At eEuroparts, we stand behind the quality of the products we sell. Every part we offer is backed by a warranty designed to give you peace of mind and protect your investment.
Standard Warranty – Most Parts
Coverage: 2 years or 24,000 miles (whichever comes first) from purchase date.
Protection: Defects in materials or workmanship under normal personal use.
Eligibility: Applies only to the original purchaser and the vehicle where the part was first installed.
Exclusions:
Wear-and-tear items (brake pads, filters, bulbs, wipers, etc.)
Commercial, fleet, rideshare, off-road, or racing use
Improper installation, misuse, accidents, or modifications
Not Covered: Labor, shipping, towing, or incidental costs.
Bison Performance Warranty – Our House Brand
Coverage: Limited Lifetime Warranty for as long as you own your vehicle.
Applies To: All products sold under the Bison Performance label.
Premium Protection: Goes beyond our standard warranty — if it’s a Bison product, the 2-year/24k mile limit is replaced with lifetime coverage.
Exclusions: Same as the standard warranty (normal wear, commercial use, improper installation, etc.).
What’s Included: Replacement of the defective product (labor and shipping excluded).
Warranty Claim Requirements
To keep claims fast and fair, we require:
Proof of purchase (invoice or order confirmation).
Photos or videos showing the defective part, order number, date, VIN, and odometer reading.
Diagnostic reports or part returns for non-visible issues may be requested.
Claims must be truthful, properly documented, and reflect normal consumer use.
Buy With Confidence: We back our products because we believe in their quality, with a transparent, customer-first warranty process you can trust. And with Bison Performance products, you’ll enjoy Limited Lifetime protection—an assurance few brands can match.
For full details and exclusions, please see our complete Warranty Terms & Conditions.
This summary is for convenience only. For full warranty coverage details, exclusions, and requirements, see our official Warranty Terms & Conditions. In case of conflict, the full policy governs.
Return Policy Overview
Most parts can be returned within 30 days of delivery if unused, uninstalled, and in original packaging.
To start a return, contact customer support via Chat or Contact Us.
Restocking fee: Up to 20% may apply for certain orders (buyer’s remorse, order errors, or special-order items)
Refunds: Issued to your original payment method within 3–5 business days after inspection
Exchanges: Not automatic — please return and reorder
Replacements: May be approved for incorrect or defective items reported within 7 days
Not returnable:
Used or installed parts
Electrical components
Opened filter kits, gaskets, or contaminated items
Final sale or custom orders
Important Notes:
Return shipping is your responsibility unless we made a verified error
Fitment is the customer’s responsibility (we can assist, but do not guarantee)
Country of origin may vary and is not grounds for return
For complete details, please see our full Return Policy.
This Returns summary is provided for convenience only. All returns, refunds, and exchanges are subject to the complete Returns Policy. In the event of any conflict, the full policy governs.
Fast, Reliable Shipping — Straight to Your Door
We ship most orders the same day when placed before 2 PM CST (Monday–Friday). Our main warehouse is just east of Nashville, TN, and we also ship from multiple locations nationwide to get your order to you as quickly as possible.
We use trusted carriers like UPS, FedEx, and USPS.
Tracking info is emailed to you as soon as your order ships.
Delivery estimates at checkout are based on carrier data, but not guaranteed.
Need help with a shipment?
If your order is missing, damaged, or incorrect, just let us know within 5 days of delivery. We’ll walk you through the quick claim process — including a few photos to help us make things right.
For complete details, please see our full Shipping Policy.
This Shipping summary is provided for convenience only. Delivery times, carrier terms, fees, restrictions, risk of loss, and other details are governed by our complete Shipping Policy. In the event of any conflict, the full policy governs.








